In general, a semiconductor process includes various kinds of processes, such as photography, diffusion, etching, chemical vapor deposition, and metal deposition, which are repeatedly performed on a silicon substrate. Among such processes, the diffusion, etching, and chemical vapor deposition are performed so that processing gases are supplied into an airtight process chamber to react on a wafer.
On the other hand, gases that are used in a semiconductor manufacturing process may have strong characteristics, such as noxiousness, combustibility, and corrosion. In the processes of manufacturing facilities, only about 10% of the processing gases takes part in the reaction, and the remaining 90% thereof that is in a non-reacted state is discharged from the manufacturing facilities.
If such noxious waste gases that are fixed gases are discharged in the atmosphere as they are without any separate purifying process, they may cause damage of peripheral manufacturing facilities, severe environmental pollution, and operator's safety accidents. Accordingly, in each of the manufacturing facilities, a scrubber is installed on a gas discharge line that is connected to an exhaust duct to decompose and purify the discharge gases into a safe state.
The scrubber is configured to use properties of the waste gases, such as explosive reaction on a general air when coming in contact with the general air, combustibility, reaction on a gas processor, and solubility in water. The scrubber may be briefly classified into a dry type, a wet type, and a mixed type that adopts both the dry type and the wet type.
The wet type scrubber is configured to collect waste gases using water, clean and cool the collected waste gases. The wet type scrubber has the advantages of a relatively simple configuration, easy manufacturing, and large capacity. However, the wet type scrubber has the drawbacks that it is unable to process water insoluble gases and in particular, it is improper to process waste gases including a hydrogen group having strong flammability.
The dry type scrubber is configured to make waste gases pass through the inside of a burner to achieve direct combustion of the waste gases or to make the waste gases pass through the inside of a high-temperature chamber that is formed using a heat source to achieve indirect combustion of the waste gases. The dry type scrubber has a prominent effect in processing flammable (combustible) gases, but is improper to process inflammable gases such as water-soluble gases.
The mixed type scrubber is configured to primarily burn waste gases in a combustion chamber to remove flammable gases and explosive gases and then to secondarily dissolve the waste gases in a water tank to dissolve the water-soluble noxious waste gases in water. The mixed type scrubber in the related art has already been disclosed in Korean Patent Application Publication No. 10-2010-0021135 entitled “Apparatus for processing waste gases”.
On the other hand, as illustrated in FIG. 5, an apparatus for purifying waste gases in the related art is configured to include a reactor 2′ into which waste gases flow through waste gas inlet ports that are downwardly installed on an upper side; a burner portion 3′ installed on an upper portion of the reactor 2′ to burn the waste gases through generation of a flame in the reactor; a water storage tank 5′ installed on a discharge pipe 4′ that is connected to a lower portion of the reactor 2′ to store water therein; and a wet cleaning portion 6′ connected to one side surface of the discharge pipe 4′ to make burnt gaseous particles pass therethrough so that the large particles are collected by water that is supplied to the inside of the wet cleaning portion 6′ to be recovered to the water storage tank 5′, and the gases are discharged to an upper portion of the wet cleaning portion 6′.
In processing the waste gases through the gas scrubber, the waste gases that are generated from a processing chamber of a semiconductor facility moves to a burner of the reactor through an injection portion, and then are burnt through combustion/oxidation or thermal decomposition. Non-processed gases or dust particles, which are not processed through the burning, move to the wet scrubber, and at this time, the wet cleaning portion performs a wetting process in which powder in the oxidized gases is separated and dropped into a water bath through spraying of the water, and discharges the cleaned gases to the air through a filter and a duct.
However, in the related art, since the burner, the reactor, and the set cleaning portion are separated from one another, the volume of the apparatus is increased to heighten space occupancy, and this may cause uneasiness of periodic maintenance of the apparatus and an increase of energy consumption for processing the semiconductor gases.